623-42-7Relevant articles and documents
Transesterification of glyceryl tributyrate with methanol using strontium borate as the solid base catalyst
Huang, Hong Sheng,Liu, Zhi Hong
, p. 1727 - 1734 (2013)
Four kinds of strontium borates were prepared and characterized by XRD, SEM, EDS, TG-DTA and Hammett titration method, and their catalytic activities were examined in the transesterification of glyceryl tributyrate with methanol for the first time. The separate effects of the molar ratio of methanol to oil, the reaction time, and reusability were investigated. In addition, the catalytic activities of Sr(OH)2 and SrCO3 were also examined for the comparison. The results showed that the basicity and catalytic activity of these catalysts were decreased as the following order: Sr(OH) 2 > SrB2O44H2O >SrB6O 105H2O >SrB2O4 >SrB 6O10 >SrCO3, and the reusability decreases as the following order: anhydrous strontium borates (SrB2O 4, SrB6O10) >hydrated strontium borates (SrB2O44H2O, SrB6O 105H2O) >Sr(OH) 2. The results indicate that the SrB2O44H2O with regular morphology, which was obtained at low temperature by a simple preparation method, might be as one kind of good potential alkaline earth salts catalyst for transesterification. Moreover, the possible reaction mechanism is proposed and analyzed. Science China Press and Springer-Verlag Berlin Heidelberg 2013.
Matsuda,Uchida
, p. 710 (1965)
The exceptional activity of a phosphazenium hydroxide catalyst incorporated onto silica in the transesterification of tributyrin with methanol
Kim, Mi-Young,Seo, Gon,Kwon, O Zoon,Chang, Duk Rye
, p. 3110 - 3112 (2009)
A phosphazenium hydroxide catalyst incorporated onto silica showed exceptional activity in the transesterification of tributyrin with methanol and could be used repeatedly without suffering any appreciable deactivation. The Royal Society of Chemistry 2009
Characterization of LipN (Rv2970c) of Mycobacterium Tuberculosis H37Rv and its Probable Role in Xenobiotic Degradation
Jadeja, Dipendrasinh,Dogra, Nandita,Arya, Stuti,Singh, Gurpreet,Singh, Gurdyal,Kaur, Jagdeep
, p. 390 - 401 (2016)
LipN (Rv2970c) belongs to the Lip family of M. tuberculosis H37Rv and is homologous to the human Hormone Sensitive Lipase. The enzyme demonstrated preference for short carbon chain substrates with optimal activity at 45C/pH 8.0 and stability between pH 6.0-9.0. The specific activity of the enzyme was 217 U/mg protein with pNP-butyrate as substrate. It hydrolyzed tributyrin to di- and monobutyrin. The active-site residues of the enzyme were confirmed to be Ser216, Asp316, and His346. Tetrahydrolipstatin, RHC-80267 and N-bromosuccinimide inhibited LipN enzyme activity completely. Interestingly, Trp145, a non active-site residue, demonstrated functional role to retain enzyme activity. The enzyme was localized in cytosolic fraction of M. tuberculosis H37Rv. The enzyme was able to synthesize ester of butyric acid, methyl butyrate, in presence of methanol. LipN was able to hydrolyze 4-hydroxyphenylacetate to hydroquinone. The gene was not expressed in in-vitro growth conditions while the expression of rv2970c gene was observed post 6h of macrophage infection by M. tuberculosis H37Ra. Under individual in-vitro stress conditions, the gene was expressed during acidic stress condition only. These findings suggested that LipN is a cytosolic, acid inducible carboxylesterase with no positional specificity in demonstrating activity with short carbon chain substrates. It requires Trp145, a non active site residue, for it's enzyme activity. J. Cell. Biochem.
Enhanced base-catalyzed activity and structural stability of nitrogen-doped carbon modified MgO-MgFe2O4 magnetic composites as catalysts for transesterification of tributyrin
Zhang, Yanhua,Zhang, Ming,Yang, Lan,Fan, Guoli,Li, Feng
, p. 6324 - 6332 (2017)
In this work, nitrogen-doped carbon modified MgO-MgFe2O4 (CN-MgFeO) magnetic composites were synthesized by a facile thermal decomposition of Mg-Fe layered double hydroxide (MgFe-LDH) and cyanamide mixture precursors. A series of comprehensive characterization studies including powder X-ray diffraction, transmission electron microscopy, Fourier transform infrared of CO2 adsorption, CO2-temperature programmed desorption, and X-ray photoelectron spectroscopy indicated that the introduction of cyanamide could finely tune the surface basicity of the resulting CN-MgFeO composites, especially surface strong Lewis basicity. Compared with CN-free MgFeO, the as-fabricated CN-MgFeO catalysts showed higher activity in the liquid-phase transesterification of tributyrin with methanol. Particularly, the CN-MgFeO composite prepared at a cyanamide/Mg molar ratio of 1.5 in the synthesis mixture gave a highest methylbutyrate yield of 80% after a reaction for 20 min. The high catalytic performance was attributable to the presence of a large amount of strong Lewis basic sites originating from highly dispersed basic MgO-MgFe2O4 mixed metal oxides and CN component in the composite. What is more, such a cost-effective CN-MgFeO catalyst had the advantages of intrinsic magnetic properties and an excellent structural stability. We expect that they may have potential practical applications in the field of industrial production of biodiesels.
Transesterification of triglycerides using nitrogen-functionalized carbon nanotubes
Villa, Alberto,Tessonnier, Jean-Philippe,Majoulet, Olivier,Su, Dang Sheng,Schl?gl, Robert
, p. 241 - 245 (2010)
Nitrogen-functionalized carbon nanotubes were synthesized by grafting amino groups to the surface of the nanotubes. The nanotubes exhibited promising results in the base-catalyzed liquid phase transesterification of glyceryl tributyrate with methanol, which is a model reaction for the production of biodiesel. The concentration of the active sites and the reaction parameters, such as temperature and glyceryl tributyrate to methanol ratio, were shown to significantly affect catalytic performance. The grafting technique employed allowed for design and control of the active sites. As a consequence, it was possible to design a nitrogen-functionalized carbon nanotube catalyst with a few strong, basic groups. This might be of interest for carbohydrate conversion reactions where strong basic sites are required but the pH of the solution should remain mild to avoid the degradation of the reactants and/or products.
MATERIALS COMPRISING CARBON-EMBEDDED IRON NANOPARTICLES, PROCESSES FOR THEIR MANUFACTURE, AND USE AS HETEROGENEOUS CATALYSTS
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Page/Page column 14, (2021/03/13)
201900257 Ausland 18 Abstract The present invention relates to catalytically active material, comprising grains of non-graphitizing carbon with iron nanoparticles dispersed therein, wherein dp, the average diameter of iron nanoparticles in the non-graphitizing carbon grains, is in the range of 1 nm to 20 nm, D, the average distance between iron nanoparticles in the non-graphitizing carbon grains, is in the range 5 of 2 nm to 150 nm, and ω, the combined total mass fraction of metal in the non-graphitizing carbon grains, is in the range of 30 wt% to 70 wt% of the total mass of the non-graphitizing carbon grains, and wherein dp, D and ω conform to the following relation: 4.5 dp / ω > D ≥ 0.25 dp / ω. The present invention, further, relates to a process for the manufacture of material according to the invention, as well as its use as a catalyst. 10
METHOD FOR PRODUCING BIO ALCOHOL FROM INTERMEDIATE PRODUCTS OF ANAEROBIC DIGESTION TANK
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Paragraph 0038-0041, (2021/05/25)
The present invention relates to a method for producing a bio-alcohol by reacting a mixture of volatile fatty acid with methanol in 2 through 11 in a reactor in the presence of a 280 °C-membered alkaline earth metal catalyst or 400 °C transition metal catalyst formed based on a support.
